1. Field of the Invention
The present invention relates generally to flow control elements. More particularly, the present invention relates to flow control elements for leak-proof cup assemblies.
2. Description of the Prior Art
Enclosed cups having drinking spouts and air vents that allow the user to drink from the spout without creating excessive vacuum in the cup, are known in the art. However, drinking spouts and air vents are liable to leak liquid stored in the cup between feedings, or if dropped, shaken, or inverted during use. Accordingly, certain cups have been developed that use valving mechanisms at the spout and at the air vent. These valves respond to suction generated during feeding to open, allowing liquid to pass through the spout and allowing air to enter the air vent when a vacuum is developed in the interior of the cup.
Three patents disclosing such valves are U.S. Pat. No. 5,079,013 to Belanger, U.S. Pat. No. 5,542,670 to Morano, and U.S. Pat. No. 6,505,445 to Manganiello, all of which are commonly owned by the assignee of the present application. Applicant has on the market a cup that employs a valve assembly that is shown in U.S. Pat. No. 6,050,445. The valve assembly is secured to the underside of the lid or cap of the cup. Applicant is also aware of a prior competitive product having a flow control element of the configuration depicted in FIG. 1, which was sold as part of the Tumble Mates Spill Proof Cup by the First Years®.
Despite the effectiveness of these cup mechanisms, applicant has discovered improved flow control elements and corresponding valve configurations that provide improved fluid flow rates without sacrificing the valves' resistance to spills or the valves' durability.